XXil INTRODUCTION.’ 
rupture of the strata and consequent local reversion of the dip, together with the 
fact of the lowest division being composed chiefly of limestone instead of sandstone, 
are unfavourable indications of the existence of a plentiful supply of deep-seated 
brine, or of nests of salt, whence the permeating waters might become saturated, 
and carry the saline matter to the surface. 
Though deficient in productive minerals, such as are reserved by the Land Office, 
a large proportion of this District consists of rich, fertile soil, well adapted to all 
agricultural purposes. Of such is a large portion of the Iowa coal-field; and the 
region lying north both of that and of the Illinois coal-field, as far as the Falls of 
the eastern tributaries of the Mississippi. Some of the lands of the Des Moines 
and Cedar Rivers can be scarcely excelled for fertility, perhaps, in the world. 
On the other hand, there are portions of the District, chiefly in the vicinity of the 
sources of the Black and Chippewa Rivers, and of the streams flowing north into 
Lake Superior, which are, in part, so hopelessly arid, that, in our generation, they 
will assuredly never be purchased or occupied; in part so covered with erratic 
boulders, that the traveller can step from one to the other, for miles, without setting 
foot on the drift-soil on which they lodge, and that a bridle-path for a pack-horse 
cannot be picked out over the country they cover; in part, again, so intersected by 
countless ponds and swamps, that fish, frogs, and water-fowl must, in our day at 
least, be their only inhabitants. | 
In conformity with my instructions, I have heretofore, from time to time, reported 
to the Department what portion of these lands are so wholly worthless, as not to 
justify, in my judgment, the expense of sectionizing, or of surveying at all, except 
so far as may be necessary to connect the surrounding surveys. These refuse lands 
amount to upwards of fifteen thousand square miles. If, in consequence of the recom- 
mendation thus made, they are excepted from the linear surveys, which are usually 
extended, by the Government, over all its Indian purchases, without examination 
or inquiry, the saving to the Land Office will much overpay the entire cost of the 
survey, the results of which I am now reporting. 
A circumstance which to some may seem trivial, will delay, to a considerable 
extent, the settlement of a portion of the District. It is the prevalence, especially 
on the Upper Wisconsin, Chippewa, St. Croix, and Black River countries, and thence 
north to Lake Superior and to the British line, of venomous insects, in such insuf- 
ferable quantities, that, at certain seasons, they destroy all comfort or quiet, by day 
or by night. Among the pineries of Northern Wisconsin, and more or less through- 
out the whole of the above designated region, the buffalo-gnat, the brulot* and the 
sand-fly, to say nothing of myriads of gigantic musquitoes, carry on incessant 
war against the equanimity of the unfortunate traveller. I and other members of 
* So called by the voyageurs from ruler, to burn; the sting producing a burning sensation. 
